14 June 1996

New niche? Dye plants on trial as natural alternative

WELD, previously thought to be a biennial, but recently performing as an annual, and a new Japanese crop offering blue colouring, are just two of a range of dye plants under trial at IACR-Long Ashton.

Such crops are still the subject of basic crop husbandry trials. But they could offer growers new niche opportunities, providing natural alternatives to synthetic dyestuffs, says Dr David Hill of Bristol University.

Weld, which produces a yellow pigment from all its aerial parts, grew surprisingly well last season, he notes. "It is normally a biennial but it really shot up last season, showing we probably have a variety which you could harvest in one year which would be a real benefit."

Promising crops

Polygonum tinctorum from Japan, being tried on a small plot for the first time this year, joins woad (indigo) and madder (red) as other promising crops. "We have shown it will grow in this country," he says.

No research has been undertaken on any such crops for about 150 years. That means most current investigations are focused on identifying potential yields, weed control, and harvesting techniques, explains Dr Hill.

A 0.5ha (1.2 acre) field scale planting of woad, due for on-site processing this summer, appears to be growing much better than the small plots being evaluated at LARS, he notes.

Green to blue…Dr David Hills tie is coloured with pigment from a new Japanese dye plant being grown at IACR-Long Ashton.